code: def _get_default_metavar_for_optional(
      self, action: argparse.Action
  ) -> str:
      return action.dest
  
file_path: dvc/dvc/cli/formatter.py
imports: import argparse
label_desc: Use image node_id 1 for calling the HelpFormatter obj's underlying member method code with example usage: obj._get_default_metavar_for_optional(action) and returns: action